Knowledge Bank

Based on the application of a rigorously quantum-mechanical hypervirial perturbation $theory,1,2$ we have generated an efficient algorithm to calculate accurately the radial functions for potential energy, vibrational adiabatic effects, and vibrational and rotational nonadiabatic effects of diatomic molecules in electronic states free from heterogeneous perturbations. The algorithm is based on analytic expressions, generated by symbolic computation verified according to two separate processors, for the coefficients $Ykl$ and $Zkl$ for the vibration-rotational terms, of which the latter coefficients are subdivided into $zklv$ for the vibration-rotational contributions of the adiabatic and nonadiabatic vibrational effects of the nuclei of each atomic number and $zklr$ for the additional rotational contributions of the nonadiabatic vibrational and rotational effects. The tables of derived parameters resulting from the fit of all available spectral lines of pure rotational and vibration-rotational transitions of HCl, AlH, LiH and $ArH+$ will be presented and the physical and chemical significance of the results will be discussed.